He moved into film editing after meeting director Hal Ashby, who was also an editor at the time.
[3] Zimmerman began his career in 1969 as an apprentice editor in music and sound effects working for the Mirisch Co. on films such as The Hawaiians, Gaily, Gaily, Little Big Man, The Godfather, Where's Papa and Jonathan Livingston Seagull.
He then became a picture assistant editor for director Hal Ashby on films such as The Landlord, Harold and Maude, Shampoo, and Being There.
[3] Zimmerman went on to work with director Hal Ashby on six films, including Coming Home, for which he received an Academy Award nomination.
The couple have five children, all of whom are in the film business: sons Dean, Danny and David are all film editors; Debi is a costumer; Dana works in post-production.